U.S. Patent Publication No. 2003/0155389 describes a slap on watch utilizing a bistable spring in the band. Separate portions of elastic material are used to attach a watch face to the band. The separate portions of elastic material attach to the band by fusing or using an adhesive.
U.S. Pat. No. 6,220,916 describes a toy band using a bistable spring in order to coil around a wrist of a wearer. A housing contains electrical components that may play a pre-recorded message. The housing has slots to attach to the band. Specifically, the band passes through the slots of the housing. The housing may be easily separated from the band and/or move relative to the band.